Field of the Invention
The present invention relates to an image processing apparatus, and an image processing method for performing an image restoration process according to an imaging apparatus and an image forming apparatus on image data to be output from the image forming apparatus.
Description of the Related Art
An imaging apparatus, such as a digital camera, and an image forming apparatus, such as a printer, each has the modulation transfer function (MTF), which is a spatial frequency characteristic. Thus, in an output image from each device, image quality deterioration (e.g., a reduction in sharpness) occurs due to the spatial frequency characteristic. Then, it is known that the degree of reduction in sharpness varies depending on the differences in method and model of the imaging apparatus or the image forming apparatus, and the difference in operation mode.
Conventionally, as an image processing apparatus for improving sharpness, there is a technique discussed in Japanese Patent Application Laid-Open No. 9-172543. Based on the spatial frequency characteristic in the process of creating image data as an image formation target and the spatial frequency characteristic in an output mode for outputting the image data, this technique sets the correction characteristic of the image data to achieve a spatial frequency characteristic (a target transfer characteristic) of the entirety of an image processing system.
In a digital camera, which is an imaging apparatus, a sharpness reduction may occur due to the blur of a lens. Thus, to reduce the sharpness reduction, then based on an instruction from a user, the process may be performed of restoring an image such that the image is less blurred. That is, even if the same imaging apparatus and the same operation mode (image capturing condition) are used, the sharpness of a captured image to be generated changes depending on an instruction from the user. Thus, even if the same camera, the same lens, and the same operation mode (image capturing condition) are used, images to be generated include both an image restored such that the optical system is less blurred, and an image that is not restored.
In the technique discussed in the publication of Japanese Patent Application Laid-Open No. 9-172543, however, an image forming apparatus cannot acquire information which indicates the degree of restoration (correction) of the sharpness reduction performed by the user as described above. Thus, if a captured image of which sharpness is adjusted to various restoration states by the user is provided to the image forming apparatus, it is not possible to perform appropriate printing sharpness restoration in the processing on the image forming apparatus side.
That is, if an image restoration process for restoring the sharpness is performed based on the spatial frequency characteristic in the process of creating image data and the spatial frequency characteristic of the image forming apparatus, the sharpness correction may be too large. This may lead to overcorrection.